Rock-drill.



. I PATENT H. A. PBDRIGK & c. A. SMITH.

ED AUG. 6, 1907.

ROCK DRILL. APPLIOATIOR TILED I412. 10. .90s.

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UNITED @TATES .ll(j)\\"AI-tl) A. PEDRIUK AND CHARLES A. SMITH; OF PHILADELPHIA, PENNSYLVANIA,

ASSIGNORS TO SAID SMITH.

ROCK-DRILL.

Specification of Letters Patent.

Patented Aug. 6, 1907.

Application tiled March 10,1906. Serial llc. 305,319-

To all whom. it. may com-mt:

be it. known that we, Howann A. PEDRICK and (HARM-1s A. Sut'ru, citizens of the United States, residing at Philadelphia, Pennsylvania, have invented certain improvements in ltoclelhills, 01' which the following is a specification.

The object of our invention is to construct a rock drill, act Hat ed by the explosion of a gaseous compound, which will withstand the severe racking strains to which arm-l; drill is subjected. This object we attain by so designing the l'tlt'k drill that there will be no direet connection between the drill plunger and the other meel'mnism ot' the drill, there being always a body wt compressible fluid back of the plunger to resist. the back lash, thus preventing the destructive jarring or racking otthe parts.

In this type of rock drill gasolene gas is preferably used as the motive lllllll, although othercxplosive mixtures can be used without departing from our invention.

Ileretot'ore in rock drills driven by an explosive mixture the great (litlieulty has been to construct a drill which will withstand the heavy shocks to which the mechanism of the drill is subjected, as it will be understood that the constant hammering of the drill against a rock which is not resilient causes a reaction on the frame which, it' the drill is not properly constructed soon shatters it and renders the drill inoperative.

Prior to our invention there has'been no drill operated by an explosive mixture which is able to stand the back lash or racking strain.

In the accompanying drawings:Figure 1, is a side view of our improved rock drill; Fig. 2, is a face view vith the fly wheel removed; Fig. 3, is a sectional cleation on the line 3-3, Fig. 1; Fig. 4, is a sectional elevation on the line 44, Fig. 2; Fig. 5, is a sectional View of the lower portion oi the cylinder; Fig. 6, is a sectional plan view on the line 6-6, Fig. 3, and Fig. 7, is a sectional view on the line 77, Fig. 6.

At the outset it will be understood that our improved drill is mounted in any suitable manner on the usual tripod. In the present instance we have shown a tripod W, in Fig. 1, carrying a slide W on which the casing of the drill is mounted, w is the usual feed screw for feeding the drill to the work. The drill is connected I to agasolene tank preferably by a flexible coupling shalt B. On one end of this crankshaft we preferably mount a fly wheel ll. v

B is a compression piston mounted in the portion A' of the cylinder A, and this piston is connected to the crank b of the shaft 15 by a connectingrod b.

c is an inlet for the explosive mixture, communicating with a carburetor C. I

In the lower portion of the casing is a plunger D con-. nected to the drill spindle, and the explosive mixture is ignited at a point between the head of the plunger and the head of the piston.

a is a passage leading from the mixing'chamber A to the interior of the cylinder A and a. is an exhaust passage leading from the interior of the cylinder A on a line in the present instance with the inlet passage.

Projecting from the head of the piston 13 is a deflector b'-' which deflects the incoming gases when the piston uncovers the inlet port so as to prevent the gases escaping at once through the exhaust passage.

In the present construction we preferably secure an extension E to the end of the casing A by bolts or other suitable lastenings and the cylindrical portion 6 of this extension E is mounted within the lower portion A of the cylinder A, forming a lining for said cylinder.

The plunger D has a deep flange d in the present instance and reciprocatcs in the lining portion e of the cylinder. I I

Connected to the plunger is a spindle D, which passes through an abutment e on the extension E and through the hub of a. right angle gear wheel D. This spindle has a longitudinal key-way d and mounted in this key-way and a key-way in the hub of the right angle gear Wheel D is a key if, so that the spindle can slide freely in the hub of the gear wheel but must turn with it. The wheel D? rests on a flange e and surrounding the hub is a sleeve 2 Mounted between the plunger D and the abutment c is a heavy coiled spring F which is compressed when the plunger is driven forward by the explosion of the gases in the cylinder, ,a washer e is preierably mounted between the spring and the abutment to increase the bearing of the spring.

The portion 6 of the extension'E forms a dash pot and in this dash pot is mounted the head D on the end of the spindle D of the plunger D. This head is so proportioned that it will come against'the underside of lniaterialf to cushion the head should the entrapped lair in the dash pot. not be sutlicient to re :t the back 'las'h.

W We preferably form an air chamber t) around the cylinder A, this air ehamber is mounted in the lower these ribs may be diseontinued at eertain points. the

Openings being preferably staggered in respeet to H'h other so that the air will have a cireuit'ous pa. age through the chamber. '1

Chamber is preferably provided with a sereen or other means to prevent impurities entering the air ehamber,

and the opposite end of the ehamber is eonneeted by a pipe 0 to the carbnreler (l. The pipe 1:" leading'lrom this air chamber to the earbtu'eter may have a valve 1" so arranged that. a eertain amount of airmay be taken in from the. atmosphere without passing through the said chamber. ly heating the air before entering the vaporizer we provide absolutely dry air and of a temperature to make the mostetlieientmixture.

Detaehably seeured to the head I) of the spindle D is the drill rod 4!.

I is the igniter plug serewed into a threaded openiiu in the eylinder A and this igniter has eonlaet. points in the present. instante and these points are in eleelrie circuit Willi a suitable eonlaet regulator 1\' so as to eream a spark at the proper time. \Ve have shown two openings for the insertion of a sparker, either one of which may be ttsed the other being elosed by a ping, We preferably lnottnt tbe eommntalor or eontar-t regulator N for regulat ing the time of the spark on one oi the bearings rtol the plates (I, as shown in Figs. 2 and I, and

40 in the present. instant-e by the eam ll whieh in this instant-e the eontaet regulator eonsists of a ring '1: mounted on the bearing a having a handle 1:. by which it can be turned and set at any point. desired. and this ring earries a spring eoutaet n'. The spring is aetuated aet nates the turning met-hanism [or the drill although a separate earn may be used if desired.

In th path of the spring is a serew eontaet point inboth the spring n.'- andpoint it. are insulated from the ring and are in the battery and igniter eireuit or may be indireelly tollllettc l to the igniter through an intensifier. 'lhis screweontaetean lHfltljltFltd towards and from. the spring to regulate the tension of the and the regulator ean beadjusted to regulate the time of spring the spark.

In order to turn th drill rod at eaeh stroke ol the spindle so that the drill point will not strike. the same plaee eonseeutively We mount. a shalt G in suitable hearings in the extension ll and on this shaft is a right angle gear wheel g whieh meshes with the right angle gear wheel I)". (in the outer end of this shaft is a nttehet wheel 1 with whit-h a spring aetnated pawl f engages. this pawl is pivoted toau arm (V rennet-ted by alinklt, toa rod ll mounted in bearin s/ton the easing A.

Set-tired to the rod it is a eollar and between this 'cellar'and on of the bearings a spring .l. (in the end of the rod ii is a l'rietion roller It whieh rests against the cam ll" on the erank shall. I), so that on eaeh revolution of the erank shalt the rod ll will be reeiproeated,

eausing the. pawl to turn the ratehet wheel intermithe inlet opening 0" to this air I the parts should the drill be prevented from turning,

as the spring will simply be compressed not; having the strength to operate the meehanism to turn the. bit until the bit. is released.

In order to (reel the eylinder we preferably form a series of radiating ribs ti on that portion of the eylinder A where the explosion takes plaee. In plaee ol' the ribs a water jaeket may be used as an equivalent.

The operation ol' ottr improved roek drill is as lol-v lows :--'the explosive mixture enters the mixing ehamher A through the feed pipe 1' and is thoroughly mixed by the rm-iproeation ot' the piston ll and when the piston is a t. the upper portion of its stroke the explosive mixture passes through the admission port It into the eylinder A between the head of the piston and the head of the plungery l 'lhd delleetor b projeeting from the piston deflecting the gases as they pass into the eylinder, the mixture eompletely filling the spaee. (in the l'orward stroke of the piston the gases are (ompressed as the spring l is of sutlieient strength to hold the plunger .1) in the tixed position while the piston is compressing the gases, and when the crank I: is on a dead eenter, as shown in l ig; 2 of the drawing with the piston at the end of its forward stroke, the gases are ignited, eansing the explosion which will overeome the pressure of the spring 1 and force the plunger l) forward, eompressing the spring and driving the drill with a positive pressure against. the stone or other material to be eut. ()n the return stroke of the piston the spent gases are exhausted through the passage 11- at the same time a fresh eharge ol' the explosive mixture enters be turned, eausing the drill rod to strike blows at dil'l'erent points on eaeh reeiproeation.

it willbe understood that. while we have deseribed the explosion taking plaee when the (rank is on a dead eenten as shown in Fig. .2, the eommutator may be so set as to ere-ate the spark either belore or alter the erank real-hes the dead tenter m nor-ding to the blow and speed desired. We have also found by experieneo that by operating the eontat't re ulator we are able to regulate the stroke of the plunger and its drill rod and in plilt'tlt't' we start. the engine by exploding on the dead renter and as it attains its required speed we atljust. the eommutator so that the spark will be made before the crank I'Ultt'llth' the dead eenter. lhis gives the most. power and the proper speed. Thus it will be seen that we eompress the gases bythe use ten, the pressure being resisted by the plunger backed by a spring which is strong enough to resist, the pressure and yet is not strong enough to resist, the explosive as this shaft is geared to the spindle D said spindle will of a pis- ,casing' and inclosing the crank shaft, thus making aforce of the mixture, and that there is no direct con-- that the forward feed of the drill does-not affect in any way the operation of the compression mechanism of the drill, as the compression mechanism is in no wise connected to or controlled by the feed. If the operator should feed too fast he simply shortens the stroke of the plunger if th'edrill cannot cut to the full depth at a single stroke, so'that all that is done is to shorten the stroke of the plunger until the drill has cut a depth equal to the amount of feed. If th'e iced is increased I so that there will be practically no reciprocation of the.

plunger and its drill rod then the drill is in effect similar to the hammer blow drill where the, drill is heldin contact with the work-and the blow is struck by a plunger on the opposite end of the drill rod, but if there is reciprocation this reciprocation .may be varied according to the amount of feed and then it becomes a variable reciprocating drill.

We preferably arrange the mechanism so that the plunger will be in direct line with the piston and the mixing chamber will be formed in the upper end of the very compact rock drill'and as the pressure is all in direct line it can heamade much lighter than if the parts were otherwise constructed.

While the mechanism is driven at such a speed that the blows are struck in rapid succession, nevertheless the action is such that the spring supported plunger will resist the action of the piston incompressing the gases while the piston also having a certain movement will resist the force of the explosion, but as the explosion takes place as'the piston is returning and as there is always space between the head of the plunger and *the head of the piston the severe racking strains are reduced to a considerable extent.

It will be understood that the blow of the drill against the rock or other material is the force of the explosion less the amount taken up in compressing the spring.

The details of the mechanism may be modified without departing from the essential features of the invention.

We claim: p

1. The combination inn rock drill actuated by the explosion of a gaseous mixture, of a cylinder, an automatically aciunicd piston and a plunger mounted in the cylinder, :1 spindle connccicd to the plunger, a spring concentrically curl-minding said spindle and opcratlvcly independent of the piston, said spring being capable of resisting the action of suld'pislon us it compresses the explosive mixture but iusuflicicni. to overcome iili. force of the explosion of said mixi.urc,.und menus for cushioning the return stroke of the plump-c1, substantially as described.

2. The combination in a rock drill, of a cylinder having on inlci for an explosive mixture and an outlet for spent gases. :1 piston and n plunger in said cylinder, a drill rodthe gases in the cylinder mounted between an abutment of the "H10 mixing chamber,

-on the crank shaft,

being of suilicient strength to resist the compression of the gases by theplston, but insuiiicient to resist the force of the explosion, and a device for cushioning the stroke of the plunger caused by said spring, substantially as descrlbcd.

4. The combination in a gas engine, ofn cylinder having an inlet for the explosive mixture and an outlet for spent gases, a piston in one end of the cylinder, automatic means for actuating the piston including a crank shaft connected thereto, a plunger on the other portion of the cylinder in line with the piston, a spindle connected to the plunger and carrying the .drill rod, :1 spring mounted with' in'the cylindcr between an abutment on the casing and the hack of the plunger, said spring being of n suliicicni strength tomcsist the action of the piston in compressing between the piston and the plunger, but not of sufilcient strength to overcome the force of the explosion of the mixture, with a dash pot for cushioning the return stroke of the plunger caused by the spring, substantially as described.

5. The combination in :1 gas engine, of a casing, :1 mixlng chamber formed in the upper portion of the casing, a crank shaft mounted in said mixing chamber, a cylinder. :1 piston mounted in the cylinder and connected to said crank shaft, said cylinder having an inlet port leading from the mixingchumbcr andan exhaust port, a plunger also in the cylinder and connccicd to the drill. n spring casing and the plunger, means for igniting an explosive charge between the piston and the plunger, with an cxtcnsiou to the casing for supporting suid abutment, said extension having :1 portion within the cylinder constructed to form :1 lining therefor. substantially as described.

6. 'lhc combinaiiou in :1 rock drill, of :1 casing iuclosiug :1 cylinder and zi-mixlng chamber, u crnuk shaft mounted in :1 pislou mounted in the cylinder and connected to the crank shaft, a passage loading from the mixing chamber to the cylinder, an outlet from the cylinder for spent gases, on extension of the casing, :1 poriion of said extension being mounlcd in the cylinder and forming a lining for the some, :1 plunger mounted in the llucd por tion of the cylinder, :1 spindle extending from the plunger through an abutment on the extension and car ring the drill 1'od,,n spring mounted between the abutment and the plunger, with menus for igniting the explosive mlxim'c at :1 point between the bend of the piston and the bond of the plunger, substantially us described.

7. The combination in a rock drill, of a casing, a mixing chamber, k1 crank shaft in the mixing chamber, :1 iiy wheel on the crank shaft, 0. cylinder, :1 piston mounted in the cylinder and connected to the crank of the crank shufi', a

passage lending from the mixing chamber to the cylinder and an outlet passage loading from the cylinder, :1 plunger, an extension to the casing having a portion forniingu lining for the cylinder and provided with an nbutmcut :1 stem on the plungcr passing through the ubutmcnt and arranged to actuate the drlll rod, :1 spring mounted between the abuimcut and ihc plunger, means for igniting the explosive mixture buiwccn the piston and the plunger. and lllcuns for turning the spindle, substantially as described.

8. The combinuilon in a rock drill, of ii. casing, a mixing chamber, :1 crank shaft in the mixing chambcig'n fly wheel a cylinder, :1 piston mounted in tho cylinder and couucclcd to the crank of the crank shaft, :1 passage leading from the mixing chamber to the cylindcr and an out let passage leading from the cylinder, :1 plunger. 21 stem on the plunger passing through an abutment and arranged to actuate the drill rod, :1 spring mounted bctwccn the abutment and thc plunger, menus for igniting the explosive mixture between the piston and the plunger, means for turning the spindle, a gear wheel through the hub of which the spindle extends, the said spindle being keyed to the hub so that it will slide therein, a second gear wheel meshing with the first gear wheel, ratchet mechanism for intermittently turning the said gearingarod con nected to the ratchet mechanism, and a driven cam for reciprocating the rod, substantially as described.

9: The combination in a rock-drill actuated by the expiosion of'ii gaseous charge, of a cylinder, apiston mounted in said cylinder, a cranit shaft connected to the piston, a fly wheel on the crank shaft, a structure forming an extension of the cylinder and provided with a portion forming a lining for a part thereof, a plunger mounted in the cylinder so as to operate within said lining, means for holding the piungerso that it will resist the compression of gases by the piston, while leaving said plunger free to move under the force of an explosion, a drill carried by the plunger,

' said cylinder having inlet and outlet ports leading to the space between the piston and the plunger, an ignitenand a cushioning device for the plunger, substantially as described.

10; The combination in a rock drill actuated by an ex lpiosive mixture, of a cylinder, a piston "and a plunger mounted in the cylinder, an air chamber surrounding that portion of tiiecylindcr containing the plunger, one end of the air chamber being open to the atmosphere and the other end thereof being connected to the carbureter oi the drill, means for operating the piston, and a device tending to maintain the plunger in a predetermined posilion, substantially as described.

12. The combination in a rock drill operated by an ex-,

v ploslve mixture, of a casing-having a cylinder formed therein, a piston in one end of the cylinder, 11 plunger in the opposite end of the cylinder, an extension secured to the end of the casing and having a portion mounted within the lower portion of the cylinder and forming a lining therefor, an air chamber formed between the lining and the casing, broken projections separating the air chamber into a number of communicating compartments, an inlet 'communicating with one portion of the air, chamber and an outlet connected to, the other portion of the air chamher, said outlet extending to'the vaporizer, substantially as described.

13.- The combination in a, rock (Hill of a frame having a cylinder, 8. plunger, :1 spindle for the plunger, an abutment on the frame through which said spindle extends a gear wheel mounted in the-abutment and splined to the spindle, a spring on 'the spindle interposed between the plunger and saidgea'r wheel, a drill rod attached to the end of the spindle, a second gear wheel meshing with saidilrst gear wheel and having a supporting'shaft ex. tending at right angles to the spindle, a ratchet whee; on said shaft, a pawl therefor, a reciprocating rod connected to the ratchet, and means for intermittently actuating said rod, substantiallyms described.

14. The combination inn rock drill, of a casing containing a cylinder, an extension of said casing having an abusmeni; and a dash pot formed therein, a plunger mounted in the cylinder, a spindle attached to the plunger and passing through the abutment and through the dash pot. a head on said spindle mounted in the dash pot, mean; for connecting a drill bit to the end of the spindle, a spring mounted around the spindle between the plunger and the abutment, a piston in the cylinder, ports leading to the space between the piston and the plunger, and means for exploding a gaseous mixture in said space, substantially as described.

15. The combination in a rock drill, oi acyllnder, a plunger therein, a dash pot in line with the cylinder, ;1 spindle attached to the plunger and extending through tl-e dash pot, a head on the spindle mounted in the dash po a spring mounted between an abutment and the plunger, with a yielding material mounted between the head and the inner end of the dash pot, substantially as describei In testimony whereof, we have signed our names to tl'"; specification, in the presence of two subscribing, witnesses HOWARD A. PEDRICK,

CHARLES A. SMITH.

'Witnesses:

WILL. A. BARR, j, Jos. H. KLEIN. 

